I was in the same boat. I have 2014 with 8.4 screen with base audio. when i added kicker dash speakers the 4 ohm speakers made it sound too "bright". I then added the kicker accessory sub and that was plug and play and has decent bass. I replaced the door speakers with Blaupunkt 6x9's, bu the stock radio just wasn't pushing them at all. I had highs and bass but no "depth" i guess you could say. I had a JL Audio 4-channel amp installed (100 watts per channel) to drive the 4 6x9 door speakers and that did the trick. Sounds great now. The amp is a class D so it is small and fits right behind the kicker sub under the back seat. I am very happy with the results to say the least.